LCD overdriving method and device and LCD

ABSTRACT

A liquid crystal display (LCD) overdriving method, an LCD overdriving device and an LCD are disclosed. The LCD overdriving method improves displaying quality and a response speed of the LCD comprising the following steps of: receiving by a scaling controller, a previous frame image grayscale value stored into a frame buffer of the scaling controller; receiving a next frame image grayscale value by the scaling controller and sending the previous frame image grayscale value and the next frame image grayscale value to a time schedule controller so that the time schedule controller looks up a lookup table and outputs an overdriving grayscale value. The present disclosure can effectively save the cost by eliminating the need of providing an additional frame buffer in the time schedule controller. Furthermore, as image grayscale values of only two pixels need to be stored in the time schedule controller, it can save more memory spaces.

BACKGROUND

1. Technical Field

The present disclosure relates to driving of liquid crystals, and moreparticularly, to a liquid crystal display (LCD) overdriving method, anLCD overdriving device, and an LCD.

2. Description of Related Art

How to shorten the response time of liquid crystals in driving of liquidcrystal displays (LCDs) has always been a challenge in the LCD industry.Particularly in presentation of a dynamic image, smearing of the dynamicimage will have a serious influence on quality of the image displayed.For example, when the image changes from a previous frame to a nextframe, the grayscale value of the image may increase; however, becauseof the low response speed of liquid crystals, it requires a relativelylong time for the grayscale value of the image to reach the expectedluminance of the next frame. In order to increase the response speed ofthe liquid crystals, a practice that is the most commonly used atpresent is to adopt overdriving; that is, by correcting a grayscalevalue of the next frame, a corresponding overdriving grayscale value isobtained and then converted into an increased driving voltage toincrease a voltage difference across the liquid crystals. In this way,the response speed of the liquid crystals can be increased to shortenthe response time thereof.

In a conventional LCD overdriving method, pixel grayscale values of theprevious frame are stored in a time schedule controller and pixelgrayscale values of the next frame are stored in a scaling controller.Because of the large scale of the pixel data, an additional frame bufferhas to be provided between the time schedule controller and the scalingcontroller to store a whole frame, which considerably increases the areaof the printed circuit board (PCB). Furthermore, when the number ofpixels increases, the memory space that is needed shall be increasedcorrespondingly. This imposes higher requirements on capacity of theframe buffer and, therefore, leads to a higher cost.

BRIEF SUMMARY OF

A primary objective of the present disclosure is to provide an LCDoverdriving method, an LCD overdriving device and an LCD that arecapable of saving the memory space and lowing the cost.

The present disclosure provides an LCD overdriving method for improvingdisplaying quality and a response speed of an LCD, comprising thefollowing steps of:

receiving, by a scaling controller, a previous frame image grayscalevalue and storing the previous frame image grayscale value into a framebuffer of the scaling controller; and

receiving a next frame image grayscale value by the scaling controllerand sending the previous frame image grayscale value and the next frameimage grayscale value to a time schedule controller so that the timeschedule controller looks up a lookup table and outputs an overdrivinggrayscale value.

Preferably, the step that the time schedule controller looks up a lookuptable and outputs an overdriving grayscale value further comprises thefollowing steps of:

receiving the previous frame image grayscale value and the next frameimage grayscale value sent by the scaling controller;

looking up the lookup table to obtain an overdriving grayscale valuecorresponding to the previous frame image grayscale value and the nextframe image grayscale value; and

outputting the overdriving grayscale value to a digital-to-analog (D/A)converter so that the D/A converter converts the overdriving grayscalevalue into an overdriving voltage.

Preferably, the step that the D/A converter converts the overdrivinggrayscale value into an overdriving voltage further comprises thefollowing steps of:

converting the overdriving grayscale value into the overdriving voltagethrough D/A conversion; and

outputting the overdriving voltage to an LCD panel to drive liquidcrystals in the LCD panel to make a response.

Preferably, sending the previous frame image grayscale value and thenext frame image grayscale value to the time schedule controller by thescaling controller is accomplished through an LVDS data interfacedisposed between the scaling controller and the time schedulecontroller.

The present disclosure further provides an LCD overdriving device,comprising:

a scaling controller, being configured to receive a previous frame imagegrayscale value and a next frame image grayscale value;

a frame buffer, being configured to store the previous frame imagegrayscale value; and

a time schedule controller, being configured to receive the previousframe image grayscale value and the next frame image grayscale valuesent by the scaling controller, look up a lookup table and output anoverdriving grayscale value.

Preferably, the time schedule controller comprises:

a grayscale value receiving module, being configured to receive theprevious frame image grayscale value and the next frame image grayscalevalue sent by the scaling controller; and

a lookup table looking-up module, being configured to look up the lookuptable to output an overdriving grayscale value corresponding to theprevious frame image grayscale value and the next frame image grayscalevalue.

Preferably, the LCD overdriving device further comprises:

a D/A converter, being configured to receive the overdriving grayscalevalue sent by the time schedule controller and convert the overdrivinggrayscale value into an overdriving voltage.

Preferably, the D/A converter comprises:

an overdriving voltage converting module, being configured to convertthe overdriving grayscale value into the overdriving voltage through D/Aconversion; and

an overdriving voltage output module, being configured to output theoverdriving voltage to an LCD panel to drive liquid crystals in the LCDpanel to make a response.

Preferably, receiving the previous frame image grayscale value and thenext frame image grayscale value by the time schedule controller isaccomplished through an LVDS data interface disposed between the scalingcontroller and the time schedule controller.

Preferably, the lookup table is built in the time schedule controller.

Preferably, the lookup table is disposed outside the LCD overdrivingdevice.

The present disclosure further comprises an LCD comprising an LCD panel,further comprising:

an overdriving device, being configured to receive an image grayscalevalue and output an overdriving voltage to the LCD panel.

According to the present disclosure, the previous frame image grayscalevalue is stored in the frame buffer instead of in the time schedulecontroller. This can effectively save the cost by eliminating the needof providing an additional frame buffer in the time schedule controller.Furthermore, as image grayscale values of only two pixels need to bestored in the time schedule controller, the problem of insufficientmemory space due to an increased amount of pixel data is avoided and thememory space of the time schedule controller is saved.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a flowchart diagram of an LCD overdriving method according tothe present disclosure;

FIG. 2 is a flowchart diagram illustrating steps of outputting anoverdriving grayscale value by a time schedule controller in the LCDoverdriving method according to the present disclosure;

FIG. 3 is a schematic view of a lookup table used in the LCD overdrivingmethod according to the present disclosure;

FIG. 4 is a flowchart diagram illustrating steps of outputting anoverdriving voltage by a D/A converter in the LCD overdriving methodaccording to the present disclosure;

FIG. 5 is a schematic structural view of an LCD overdriving deviceaccording to the present disclosure;

FIG. 6 is a schematic structural view of a time schedule controller inthe LCD overdriving device according to the present disclosure;

FIG. 7 is a schematic structural view of the LCD overdriving device(comprising a D/A converter) according to the present disclosure;

FIG. 8 is a schematic structural view of the D/A converter in the LCDoverdriving device according to the present disclosure; and

FIG. 9 is a schematic structural view of an LCD (comprising anoverdriving device and an LCD panel) according to the presentdisclosure.

Hereinafter, implementations, functional features and advantages of thepresent disclosure will be further described with reference toembodiments thereof and the attached drawings.

DETAILED DESCRIPTION OF THE DISCLOSURE

It shall be understood that, the embodiments described herein are onlyintended to illustrate but not to limit the present disclosure.

Referring to FIG. 1, there is shown a flowchart diagram of an LCDoverdriving method according to the present disclosure. The LCDoverdriving method is used to improve the displaying quality and theresponse speed of an LCD, and comprises the following steps.

Step S10: receiving, by a scaling controller, a previous frame imagegrayscale value and storing the previous image grayscale value into aframe buffer of the scaling controller.

In this embodiment, pixel data of the previous frame is stored in theframe buffer of the scaling controller instead of the time schedulecontroller. This eliminates the need of providing an additional framebuffer in the time schedule controller and significantly saves thememory space in the time schedule controller.

Step S20: receiving a next frame image grayscale value by the scalingcontroller and sending the previous frame image grayscale value and thenext frame image grayscale value to a time schedule controller so thatthe time schedule controller looks up a lookup table and outputs anoverdriving grayscale value.

In this embodiment, the image grayscale values are transmitted in unitsof one pixel. When the grayscale value of one pixel of the next framearrives in the scaling controller, the scaling controller retrieves fromthe frame buffer the grayscale value of a corresponding pixel in theprevious frame and sends the grayscale values of the previous frame andthe next frame to the time schedule controller. In this case, imagegrayscale values of only two pixels need to be stored in the timeschedule controller, so it is unnecessary to provide an additional framebuffer in the time schedule controller, thus saving the cost. Meanwhile,once outputting of the overdriving grayscale value is completed, thetime schedule controller releases the image grayscale values in thememory space so as to receive image grayscale values corresponding to anext pixel in the previous frame and the next frame. In this way, theproblem of insufficient memory space when pixel data of a whole framehas to be stored is avoided and the memory space of the time schedulecontroller is saved.

Referring to FIG. 2, there is shown a flowchart diagram illustratingsteps of outputting an overdriving grayscale value by a time schedulecontroller in the LCD overdriving method according to the presentdisclosure. In the step S20 described above, the step that the timeschedule controller looks up a lookup table and outputs an overdrivinggrayscale value further comprises the following steps.

Step S21: receiving the previous frame image grayscale value and thenext frame image grayscale value sent by the scaling controller.

In this embodiment, transmission of the previous frame image grayscalevalue and the next frame image grayscale value is accomplished throughan LVDS data interface between the scaling controller and the timeschedule controller. The image grayscale values are transmitted in unitsof one pixel, and grayscales corresponding to a same pixel location in aprevious frame and a next frame are transmitted at a time, so the timeschedule controller only needs to store grayscales of two pixels at atime. This saves the memory space of the time schedule controller.

Step S22: looking up the lookup table to obtain an overdriving grayscalevalue corresponding to the previous frame image grayscale value and thenext frame image grayscale value.

In this embodiment, the overdriving grayscale value is obtained byenabling the time schedule controller to look up the lookup table builtin the time schedule controller (the lookup table may also be disposedin a memory external to the LCD overdriving device). In the lookuptable, the previous frame image grayscale value and the next frame imagegrayscale value of a same pixel location correspond to one overdrivinggrayscale value.

Step S23: outputting the overdriving grayscale value to adigital-to-analog (D/A) converter so that the D/A converter converts theoverdriving grayscale value into an overdriving voltage.

In this embodiment, the overdriving image grayscale value in a digitalform is converted by the D/A converter into an overdriving voltage in ananalog form, which is then applied across the liquid crystals. As theoverdriving voltage is higher than the original driving voltage, theresponse speed of the liquid crystals gets increased and the responsetime of the liquid crystals is shortened.

Referring to FIG. 3, there is shown a schematic view of a lookup tableused in the LCD overdriving method according to the present disclosure.

In the lookup table of this embodiment, the first column of values areprevious frame image grayscale values, the first row of values are nextframe image grayscale values, and other values are overdriving grayscalevalues. When a previous frame image grayscale value is identical to anext frame image grayscale value, the overdriving grayscale valueoutputted is also identical to both the first frame image grayscalevalue and the next frame image grayscale value; and when the previousframe image grayscale value is different from the next frame imagegrayscale value, the overdriving grayscale value is just a valuecorresponding to the row where the previous frame image grayscale valueis located and the column where the next frame image grayscale value islocated in the lookup table. For example, if the previous frame imagegrayscale value is c and the next frame image grayscale value is d, thena value cd located in the c^(th) row and the d^(th) column is just thecorresponding overdriving grayscale value. Then, the value cd isoutputted to the D/A converter to be converted into an overdrivingvoltage. In this way, the magnitude of the driving voltage is altered toshorten the response time of the liquid crystals and improve displayingquality of the LCD.

Referring to FIG. 4, there is shown a flowchart diagram illustratingsteps of outputting an overdriving voltage by a D/A converter in the LCDoverdriving method according to the present disclosure. As shown in FIG.4, in the step S23 described above, the process in which the D/Aconverter converts the overdriving grayscale value into an overdrivingvoltage further comprises the following steps.

Step S231: converting the overdriving grayscale value into theoverdriving voltage through D/A conversion; and

Step S232: outputting the overdriving voltage to an LCD panel to driveliquid crystals in the LCD panel to make a response.

In this embodiment, the overdriving image grayscale value in a digitalform is converted by the D/A converter into an overdriving voltage in ananalog form, which is then applied across the liquid crystals. As theoverdriving voltage is higher than the original driving voltage, theresponse speed of the liquid crystals gets increased and the responsetime of the liquid crystals is shortened.

Referring to FIGS. 5 to 8, FIG. 5 is a schematic structural view of anLCD overdriving device according to the present disclosure; FIG. 6 is aschematic structural view of a time schedule controller in the LCDoverdriving device according to the present disclosure; FIG. 7 is aschematic structural view of the LCD overdriving device (comprising aD/A converter) according to the present disclosure; and FIG. 8 is aschematic structural view of the D/A converter in the LCD overdrivingdevice according to the present disclosure.

As shown in FIG. 5, an LCD overdriving device 100 according to thepresent disclosure comprises:

a scaling controller 10, being configured to receive a previous frameimage grayscale value and a next frame image grayscale value;

a frame buffer 11, being configured to store the previous frame imagegrayscale value; and

a time schedule controller 20, being configured to receive the previousframe image grayscale value and the next frame image grayscale valuesent by the scaling controller 10, look up a lookup table and output theoverdriving grayscale value.

In this embodiment, the frame buffer 11 is disposed in the scalingcontroller 10, and the scaling controller 10 receives pixel data of theprevious frame and stores it into the frame buffer 11. This eliminatesthe need of providing an additional frame buffer in the time schedulecontroller 20 and significantly saves the memory space in the timeschedule controller 20. Furthermore, the image grayscale values aretransmitted in units of one pixel. When the grayscale value of one pixelof the next frame arrives in the scaling controller 10, the scalingcontroller 10 retrieves from the frame buffer 11 the grayscale value ofa corresponding pixel in the previous frame and sends the grayscalevalues of the previous frame and the next frame to the time schedulecontroller 20. In this case, image grayscale values of only two pixelsneed to be stored in the time schedule controller 20, so it isunnecessary to provide an additional frame buffer in the time schedulecontroller 20, thus significantly saving the cost. Meanwhile, onceoutputting of the overdriving grayscale value is completed, the timeschedule controller 20 releases the image grayscale values in the memoryspace so as to receive image grayscale values corresponding to a nextpixel in the previous frame and the next frame. In this way, the problemof insufficient memory space when pixel data of a whole frame has to bestored is avoided and the memory space of the time schedule controller20 is saved.

As shown in FIG. 6, the time schedule controller 20 comprises:

a grayscale value receiving module 21, being configured to receive theprevious frame image grayscale value and the next frame image grayscalevalue sent by the scaling controller 10; and

a lookup table looking-up module 22 for looking up the lookup table tooutput an overdriving grayscale value corresponding to the previousframe image grayscale value and the next frame image grayscale value.

In this embodiment, an LVDS data interface is disposed between thescaling controller 10 and the time schedule controller 20 to accomplishtransmission of the previous frame image grayscale value and the nextframe image grayscale value. The image grayscale values are transmittedin units of one pixel, and only grayscales of a same pixel location in aprevious frame and a next frame are transmitted at a time, so the timeschedule controller 20 only needs to store grayscales of two pixels at atime. This saves the memory space of the time schedule controller 20.The overdriving grayscale value is obtained by the lookup tablelooking-up module 22 through accessing an external lookup table or alookup table built in the time schedule controller 20. In the lookuptable, the previous frame image grayscale value and the next frame imagegrayscale value of a same pixel location correspond to one overdrivinggrayscale value.

As shown in FIG. 7, the LCD overdriving device 100 further comprises:

a D/A converter 30, being configured to receive the overdrivinggrayscale value sent by the time schedule controller 20 and convert theoverdriving grayscale value into an overdriving voltage.

In this embodiment, the overdriving image grayscale value in a digitalform is converted into an overdriving voltage in an analog form, whichis then applied across the liquid crystals. As the overdriving voltageis higher than the original driving voltage, the response speed of theliquid crystals gets increased and the response time of the liquidcrystals is shortened.

As shown in FIG. 8, the D/A converter 30 comprises:

an overdriving voltage converting module 31, being configured to convertthe overdriving grayscale value into the overdriving voltage through D/Aconversion; and

an overdriving voltage output module 32, being configured to output theoverdriving voltage to an LCD panel to drive liquid crystals in the LCDpanel to make a response.

In this embodiment, the overdriving image grayscale value in a digitalform is converted by the overdriving voltage converting module 31 intoan overdriving voltage in an analog form, which is then applied by theoverdriving voltage output module 32 across the liquid crystals. As theoverdriving voltage is higher than the original driving voltage, theresponse speed of the liquid crystals gets increased and the responsetime of the liquid crystals is shortened.

In this embodiment, the pixel data of the previous frame image grayscalevalues is stored in the frame buffer 11 instead of in the time schedulecontroller 20. This eliminates the need of providing an additional framebuffer in the time schedule controller 20 and can significantly save thememory space in the time schedule controller 20. Furthermore, when thegrayscale value of one pixel of the next frame arrives in the scalingcontroller 10, the scaling controller 10 sends the grayscale values ofthe previous frame and the next frame to the time schedule controller20. In this case, image grayscale values of only two pixels need to bestored in the time schedule controller 20, so it is unnecessary toprovide an additional frame buffer in the time schedule controller 20,thus saving the cost. Meanwhile, once outputting of the overdrivinggrayscale value is completed, the time schedule controller 20 releasesthe image grayscale values in the memory space so as to receive imagegrayscale values corresponding to a next pixel in the previous frame andthe next frame. In this way, the problem of insufficient memory spacewhen pixel data of a whole frame has to be stored is avoided and thememory space of the time schedule controller 20 is saved.

Referring to FIG. 9, there is shown a schematic structural view of anLCD (comprising an overdriving device and an LCD panel) according to thepresent disclosure. As shown in FIG. 9, the LCD of this embodimentcomprises an overdriving device 100, which is configured to receive animage grayscale value and output an overdriving voltage to an LCD panel200.

The overdriving device 100 comprises a scaling controller 10, a framebuffer 11 of the scaling controller 10, a time schedule controller 20and a D/A converter 30. The scaling controller 10 is configured toreceive a previous frame image grayscale value and store it into theframe buffer 11 of the scaling controller 10. The scaling controller 10is further configured to receive a next frame image grayscale value and,through an LVDS data interface, send the previous frame image grayscalevalue and the next frame image grayscale value to the time schedulecontroller 20. The time schedule controller 20 is configured to obtainan overdriving grayscale value by looking up the lookup table and outputthe overdriving grayscale value to the D/A converter 30. The D/Aconverter 30 is configured to convert the overdriving grayscale valueinto an overdriving voltage for output to the LCD panel 200.

In this embodiment, the pixel data of the previous frame image grayscalevalues is stored in the frame buffer 11 instead of in the time schedulecontroller 20. This eliminates the need of providing an additional framebuffer in the time schedule controller 20 and can significantly save thememory space in the time schedule controller 20. Furthermore, when thegrayscale value of one pixel of the next frame arrives in the scalingcontroller 10, the scaling controller 10 sends the grayscale values ofthe previous frame and the next frame to the time schedule controller20. In this case, image grayscale values of only two pixels need to bestored in the time schedule controller 20, so it is unnecessary toprovide an additional frame buffer in the time schedule controller 20,thus saving the cost. Meanwhile, once outputting of the overdrivinggrayscale value is completed, the time schedule controller 20 releasesthe image grayscale values in the memory space so as to receive imagegrayscale values corresponding to a next pixel in the previous frame andthe next frame. In this way, the problem of insufficient memory spacewhen pixel data of a whole frame has to be stored is avoided and thememory space of the time schedule controller 20 is saved.

What described above are only preferred embodiments of the presentdisclosure but are not intended to limit the scope of the presentdisclosure. Accordingly, any equivalent structural or process flowmodifications that are made on basis of the specification and theattached drawings or any direct or indirect applications in othertechnical fields shall also fall within the scope of the presentdisclosure.

The invention claimed is:
 1. A liquid crystal display (LCD) overdrivingmethod for improving displaying quality and a response speed of an LCD,comprising the following steps of: receiving, by a scaling controller, aprevious frame image grayscale value and storing the previous frameimage grayscale value into a frame buffer of the scaling controller; andreceiving a next frame image grayscale value by the scaling controllerand sending the previous frame image grayscale value and the next frameimage grayscale value to a time schedule controller independent from thescaling controller so that the time schedule controller looks up alookup table and outputs an overdriving grayscale value; wherein theprevious frame image grayscale value and the next frame image grayscalevalue are sent to the time schedule controller pixel by pixel, whenoutputting of a overdriving grayscale value of a pixel is completed, theprevious frame image grayscale value and the next frame image grayscalevalue of the pixel are removed from a memory space of the time schedulecontroller and then a previous frame image grayscale value and a nextframe image grayscale value of a next pixel are stored in the memoryspace.
 2. The LCD overdriving method of claim 1, wherein the step thatthe time schedule controller looks up a lookup table and outputs anoverdriving grayscale value further comprises the following steps of:receiving the previous frame image grayscale value and the next frameimage grayscale value sent by the scaling controller; looking up thelookup table to obtain an overdriving grayscale value corresponding tothe previous frame image grayscale value and the next frame imagegrayscale value; and outputting the overdriving grayscale value to adigital-to-analog (D/A) converter so that the D/A converter converts theoverdriving grayscale value into an overdriving voltage.
 3. The LCDoverdriving method of claim 2, wherein the step that the D/A converterconverts the overdriving grayscale value into an overdriving voltagefurther comprises the following steps of: converting the overdrivinggrayscale value into the overdriving voltage through D/A conversion; andoutputting the overdriving voltage to an LCD panel to drive liquidcrystals in the LCD panel to make a response.
 4. The LCD overdrivingmethod of claim 1, wherein sending the previous frame image grayscalevalue and the next frame image grayscale value to the time schedulecontroller by the scaling controller is accomplished through an LVDSdata interface disposed between the scaling controller and the timeschedule controller.
 5. An LCD overdriving device, comprising: a scalingcontroller, being configured to receive a previous frame image grayscalevalue and a next frame image grayscale value; a frame buffer, beingconfigured to store the previous frame image grayscale value; and a timeschedule controller independent from the scaling controller, beingconfigured to receive the previous frame image grayscale value and thenext frame image grayscale value sent by the scaling controller, look upa lookup table and output an overdriving grayscale value; wherein theprevious frame image grayscale value and the next frame image grayscalevalue are sent to the time schedule controller pixel by pixel, whenoutputting of a overdriving grayscale value of a pixel is completed, theprevious frame image grayscale value and the next frame image grayscalevalue of the pixel are removed from a memory space of the time schedulecontroller and then a previous frame image grayscale value and a nextframe image grayscale value of a next pixel are stored in the memoryspace.
 6. The LCD overdriving device of claim 5, wherein the timeschedule controller comprises: a grayscale value receiving module, beingconfigured to receive the previous frame image grayscale value and thenext frame image grayscale value sent by the scaling controller; and alookup table looking-up module, being configured to look up the lookuptable to output an overdriving grayscale value corresponding to theprevious frame image grayscale value and the next frame image grayscalevalue.
 7. The LCD overdriving device of claim 5, further comprising: aD/A converter, being configured to receive the overdriving grayscalevalue sent by the time schedule controller and convert the overdrivinggrayscale value into an overdriving voltage.
 8. The LCD overdrivingdevice of claim 7, wherein the D/A converter comprises: an overdrivingvoltage converting module, being configured to convert the overdrivinggrayscale value into the overdriving voltage through D/A conversion; andan overdriving voltage output module, being configured to output theoverdriving voltage to an LCD panel to drive liquid crystals in the LCDpanel to make a response.
 9. The LCD overdriving device of claim 5,wherein receiving the previous frame image grayscale value and the nextframe image grayscale value by the time schedule controller isaccomplished through an LVDS data interface disposed between the scalingcontroller and the time schedule controller.
 10. The LCD overdrivingdevice of claim 5, wherein the lookup table is built in the timeschedule controller.
 11. The LCD overdriving device of claim 5, whereinthe lookup table is disposed outside the LCD overdriving device.
 12. AnLCD comprising an LCD panel and an overdriving device, being configuredto receive an image grayscale value and output an overdriving voltage tothe LCD panel, the overdriving device comprising: a scaling controller,being configured to receive a previous frame image grayscale value and anext frame image grayscale value; a frame buffer, being configured tostore the previous frame image grayscale value; and a time schedulecontroller independent from the scaling controller, being configured toreceive the previous frame image grayscale value and the next frameimage grayscale value sent by the scaling controller, look up a lookuptable and output an overdriving grayscale value; wherein the previousframe image grayscale value and the next frame image grayscale value aresent to the time schedule controller pixel by pixel, when outputting ofa overdriving grayscale value of a pixel is completed, the previousframe image grayscale value and the next frame image grayscale value ofthe pixel are removed from a memory space of the time schedulecontroller and then a previous frame image grayscale value and a nextframe image grayscale value of a next pixel are stored in the memoryspace.
 13. The LCD of claim 12, wherein the time schedule controllercomprises: a grayscale value receiving module, being configured toreceive the previous frame image grayscale value and the next frameimage grayscale value sent by the scaling controller; and a lookup tablelooking-up module, being configured to look up the lookup table tooutput an overdriving grayscale value corresponding to the previousframe image grayscale value and the next frame image grayscale value.14. The LCD of claim 12, further comprising: a D/A converter, beingconfigured to receive the overdriving grayscale value sent by the timeschedule controller and convert the overdriving grayscale value into anoverdriving voltage.
 15. The LCD of claim 14, wherein the D/A convertercomprises: an overdriving voltage converting module, being configured toconvert the overdriving grayscale value into the overdriving voltagethrough D/A conversion; and an overdriving voltage output module, beingconfigured to output the overdriving voltage to an LCD panel to driveliquid crystals in the LCD panel to make a response.
 16. The LCD ofclaim 12, wherein receiving the previous frame image grayscale value andthe next frame image grayscale value by the time schedule controller isaccomplished through an LVDS data interface disposed between the scalingcontroller and the time schedule controller.
 17. The LCD of claim 12,wherein the lookup table is built in the time schedule controller. 18.The LCD of claim 12, wherein the lookup table is disposed outside theLCD overdriving device.